The field of invention relates to the transmission of signals for emergency vehicles. More specifically, this present invention relates to a system for transmitting signals from emergency vehicles to nearby commuter vehicles.
Various methods and devices have been used to transmit a signal or warning from an emergency vehicle to nearby vehicles, such as the siren of a fire truck or ambulance. Another method involves sending a signal from the emergency vehicle to the traffic light at an upcoming intersection. The traffic light is programmed to turn red in all directions when the traffic light receives the signal.
Sirens have several disadvantages. The volume of the siren limits the distance at which the siren can be heard. Excessive volume can be damaging to the ears of commuters, pedestrians, and the occupants of the emergency vehicle. An additional disadvantage of siren alerts is that commuters have difficulty discerning how many emergency vehicles are in the area or knowing the direction the emergency vehicles are traveling. One emergency vehicle sounding a siren can pass by the commuter vehicle. The commuter may erroneously assume that only one emergency vehicle is in the vicinity and resume travel on the road once the first emergency vehicle passes. In many circumstances, a second emergency vehicle is traveling some distance behind the first emergency vehicle, catching the commuter unaware as he or she enters the path of the second emergency vehicle. Such a situation can force the second emergency vehicle to swerve around the commuter's vehicle, creating a hazard to occupants of the commuter vehicle, the second emergency vehicle, as well as other vehicles in the vicinity.
Another disadvantage associated with the use of sirens is that many commuter vehicles are constructed with a much quieter interior than in past years. The quiet vehicles make it more difficult to hear outside noises, including the blare of a siren. More people live in urban cities and fewer people reside in sparsely traveled rural areas. The cities are densely populated and noisy, which hinders the ability of drivers to adequately hear and discern the siren, above the loud background noises. Additionally, cities have large, tall buildings that block the transmission of the siren sound. The siren sound tends to be funneled down the street. The siren sound does not effectively go around corners. Sound waves can bounce off of buildings and travel around corners to a certain limit, but sound waves do have a tendency to continue travel in the preexisting unobstructed direction.
Sending a signal from the emergency vehicle to a traffic light also has disadvantages. The emergency vehicle transmits a signal to the traffic light at an upcoming intersection. The traffic light responds by turning the traffic signals red in all directions. Commuter traffic is halted, allowing the emergency vehicle to pass easily through the intersection.
Installing the transmitter device on each emergency vehicle is only a small portion of the cost. Each traffic light must have a receiver installed. Installing the receiver on new traffic lights can be expensive. The costs are even more prohibitive when the existing traffic lights need to be retrofitted with a receiver. Coordinating the halting of traffic during the installation can be very time consuming and disruptive to commuters. The cost of retrofitting all of the traffic signals in a city is borne by the city government. The costs can be prohibitive and most cities decline to use the method.
An effective emergency vehicle alert system is very important. Many lives are lost each year in vehicle accidents involving emergency vehicles. Methods and systems are needed that will minimize the risk of the emergency vehicle incurring a collision with a commuter vehicle, which results in injury or death. An emergency vehicle alert system that transmitted a signal farther than the hearing range of a siren would allow commuter vehicles to pull to the side of the road sooner. The roads would be less obstructed and the emergency vehicle could travel faster, reaching the accident scene sooner and delivering patients to treatment centers more rapidly.
Therefore, there is a need for an emergency vehicle alert system that will transmit a signal farther than the hearing range of a siren. Furthermore, there is a need for a system that is affordable to implement. Additionally the emergency vehicle alert system should provide an indication when more than one emergency vehicle is present in the vicinity. The system should also provide an indication of the relative position of the emergency vehicle(s) in relation to the commuter vehicle.